1. Field
The present disclosure relates to a method for fabricating a semiconductor device, and more specifically to a method for fabricating a nonvolatile memory device.
2. Description of the Related Art
In order to satisfy consumers' demand for excellent performance and low priced semiconductor memory devices, highly integrated semiconductor devices are required. In particular, the integration level of semiconductor devices is an important factor in determining the price of products. Thus, demands for highly integrated semiconductor devices are gradually increasing. Conventional two-dimensional or planar semiconductor memory devices are greatly influenced by the technology of patterning of finer components because the integration level is chiefly determined by the area occupied by a unit memory cell.
However, the highest-priced equipment may be used to achieve patterning of finer components of a memory device. Therefore, there may still be limits to the capability of the conventional two-dimensional semiconductor memory device even with increasing integration levels. To overcome these limits, research into a vertical cell string structure having a plurality of memory cells stacked in a three-dimensional manner is being conducted.
Highly integrated nonvolatile memory devices having a vertically stacked memory cell structure have led to a need for a mold structure included in the nonvolatile memory device to have enhanced mechanical strength.